Currently available surgical treatment methods for certain medical disorders, such as epilepsy or other seizure related disorders, may include stimulation of the nervous system by vagus nerve stimulation (VNS), which has been approved by the U.S. Food and Drug Administration (FDA). In this method, stimulating electrodes are surgically implanted in contact with the vagus nerve as it passes through the neck. In addition to complications related to anesthesia, potential for infection, cost, and other adverse events with VNS, many of the subjects who undergo VNS treatments do not achieve relief, and there is no reliable predictor of good outcomes from the implanted VNS device.
Other approaches to neuromodulation are the focus of on-going research. For example, implantable approaches are also being studied, including deep brain stimulation (DBS) of specific brain regions, and intracranial stimulation of the same via a device which monitors brain activity and delivers stimuli as needed. However, the risks of DBS include infection, hemorrhage, and injury to deep brain structures.
In some clinical situations, electroconvulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS) have been used for neurological and psychiatric conditions. Traditionally, brain stimulation has been a primary treatment alternative to medications and psychotherapy, and ECT has been the dominant brain stimulation approach since the first part of the 20th century. However, ECT carries risks of memory and other cognitive side effects, considerable cost, and risks of anesthesia.
Many of the above-described methods are invasive and may have considerable costs and side effects. Further, a substantial percentage of patients do not recover from or get adequate lasting relief for the condition or disorder despite multiple trials of pharmaceutical or surgical treatment.
The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded as subject matter by which the scope of the invention is to be bound.